All eyes will be on “Saturday Night Live” tonight to see how the “Not Ready for Primetime Players” skewer news of Osama bin Laden’s death. We have a hint of their plans. Sources tell us that they spotted this week’s host, Tina Fey, in rehearsals playing Ariel from “The Little Mermaid.” Fey, done up as a mermaid, was leading the full “SNL” cast in a musical showstopper of the classic Disney tune “Under the Sea.” For the number’s finale, bin Laden’s corpse is “dropped from the rafters,” according to our source, and into the drink, lampooning the terrorist’s trip to a watery grave. It’s unclear which “SNL” cast members will take on the other beloved “Little Mermaid” characters (though Bill Hader does look like a crab). Not all “SNL” sketches make it from rehearsals on to the show, but we sure hope this one does. An “SNL” rep could not be reached for comment.